Solar battery trickle charger

[halftonstude]

Diodes will create voltage drop between The batteries .3 for selenium up to .7 for silicon and will prevent downstream batteries from being kept at the correct voltage... As for multiple batteries in parallel maintenance isn’t much... milliamperes. It’s the 1.5 amps that would be seriously affected and wouldn’t have enough oomph to charge the three to get them to the point where the charger switches to maintenance. Could work but would take way longer. Batteries provide and use ampere hours... reduce the amps requires more hours.

[john2189]

Ok, so over winter, it should work?

[inairam]

Golf cart batteries 36 or 48 volts are charged as one 36v or 48 volt battery. LI-io batteries made up a series of cells need a battery management system (BMS) which help keep the various batteries in series within the correct range. That is what the electric cars have to manage the battery bank from one charger.

The safest for the battery thing to do it charge the batteries individually. Not practical with golf carts or other large batter banks like solar.

If you do try to charge various batteries off of one charger they should all be the same type of battery 12 lead acid, 12v gel, 12 v sealed and about the same age/ condition. A weak battery can hurt the other batteries in the bank.

Also the + and - from the charger should be on different batteries. The first battery should be one and the last battery should be the other. This helps keep the battery bank uniform

My family had a number of electric golf carts for many years and you learn a lot about batteries.

[halftonstude]

Batteries are my life, i'm an EE with at&t, that's just about all i do. For charging multiple batteries or cells in series as inairam says, the batteries have to be identical - same age, manufacturer, size, type, style, chemistry etc. But that's what you'd have in a golf cart, 3 or 4 12 volt monoblocks that are all the same - or close enough to the same that the minute variations (age for instance) won't matter. For charging multiple 12 volt batteries in parallel, all that matters is they're the same chemistry and voltage; the charger just maintains a constant output and each battery takes its own current requirements. However, if the charger isn't big enough, all batteries will suffer in either series or parallel configurations. The maintainer changes the internal electronics and does all sorts of magic with the charge current, and spreading that over multiple batteries would not properly maintain them as you said. Small chargers should be kept to a single battery within its size range. Our battery banks are absolutely enormous. Rooms full of them. The 2 volt cells range from just a few pounds to 800 pounds per cell (remember your 12 volt car battery has 6 cells and weighs about 25 pounds...) We've got 24 volt batteries, 48, 130, 140, 240, 480, and 540 volt battery strings. Chemistries range from flooded lead acid to valve regulated lead acid, ni-cad, lithium ion are ALL gone, Lithium metal polymer aren't made anymore, i've tested the only two molten sodium products manufactured now (you read that right... the batteries operate at around 300 celsius and the anode is molten sodium metal, electrolyte is a molten metallic salt). keeping the battery at room temperature, or basement temperature is fantastic. cooler the better but not freezing. The difference between a maintainer and a trickle charger is that the maintainer doesn't constantly keep charge current going into the battery like the trickle charger does. that ages a battery. The longer the battery stays on charge after the battery is fully charged, the more the positive plates oxidize, and that's the primary means of failure within a flooded lead acid cell. I've just replaced the start battery on my diesel generator, 18 years old for a cranking battery isn't too bad. if the battery stays discharged too long that damages it as well as the sulfate crystals grow larger which makes them harder to put back into solution. it can be done, temperature, voltage and time, but it takes a long time and if it's been sitting too long you might not be able to bring it back (excessive sulfation or hydration is not reversible) ok i'm rambing time to stop. thanks
c

[Bob McCarty]

A friend sent me a link about using EDTA to rejuvenate batteries. Can you comment on that?

[inairam]

The difference between a maintainer and a trickle charger is that the maintainer doesn't constantly keep charge current going into the battery like the trickle charger does. that ages a battery. The longer the battery stays on charge after the battery is fully charged, the more the positive plates oxidize, and that's the primary means of failure within a flooded lead acid cell.

to be clear you are saying the maintainer is better than the trickle charger- correct?

Also I have seen some charger/ maintainers say they have a sulfidation cycle. is that important? do those sulfidation cycles work? I know they are recommended for solar battery banks.

[BigBill]

I need a bigger battery box in my fcub. I want a bigger battery to go with the 105 amp alternator. Plowing at night with the airport runway 12v headlights shouldn’t be a problem.
I used these headlights in my 154 already.

I have many new battery tenders but haven’t used any yet. One for each tractor. Another project.

[Waif]

Question. Could two or three batteries be hooked up parallel to one maintainer?

Yes , but would that be effective? If they were identical batteries size,capacity, and condition , and the unit charging or maintaining them can handle the job....Maybe.

A multibank maintainer /charger would treat them as individuals. Better suiting individual differences.
In 12 volt , the marine type might be a choice.

[Dusty B]

Had a z-Barr solar fence charger go bad! The solar panel was 6 V - Electrcian friend hooked up the solar panel w/leads. Haven’t been able to give it a true test to see if it would really charge or maintain a dead 6 V battery! Also have 2 12v solar panels on close out sale from Menards - have not been able to give them a true test! (Next summer project,)!

[halftonstude]

Sorry for the delay in reply inairam and bob, just found some granary weevils in our pasta and spent two days cleaning... First question is about EDTA, and i'm hesitant to answer here because this thread is about solar trickle charger. (so experts and moderators, what's the best thing to do then?) I'll be brave and provide my reply here, please let me know how to proceed next time this happens.

Ethylenediaminetetraacetate (or EDtetraacetic acid) is a chemical found in many places including shampoo. The reason it is recommended (I don't) for rejuvenating batteries is because lead sulfate can be dissolved into it. Many people hear a battery has sulfated and they say their battery is toast - not so. Sulfation of both the positive and negative plates is the reaction by which electricity is generated in the battery - it has to happen. When the battery is recharged, the sulfate goes back from the plates into solution again and all is well. However, if the sulfate is left on the plates for too long (i.e. the battery is left discharged), the tiny crystals start to form together into larger crystals, which are much more difficult to charge off. It can be done but takes more voltage and lots of time. Any lead (negative plate) or lead dioxide (positive plate) that has large crystals of lead sulfate that can't be converted back into active material is lost capacity. This is one of the means by which a battery starts to deteriorate and slowly lose its ability to perform. By washing the plates with a solution with EDTA you're effectively taking the sulfate off the plates and exposing better active material below. So in one regards the battery can function better because more active material is available for conversion to electricity, but on the other hand you've just washed away material that used to make electricity and you've lost capacity of your battery. short term gain long term loss. I used the word function because it cannot perform better - material and capacity has been lost and won't come back; the battery doesn't have the chemistry to make as much electricity as it could before.

Is a maintainer better than a trickle charger? that's like asking if a fork is better than a spoon. They each have their purpose and both do their job very well. Before the invention of smart chargers, or even maintainers, all there was were trickle chargers. As the battery (most chemistries of batteries anyway) comes closer to full charge the internal resistance climbs and basically limits the charging current. You could put a 400 amp charger on our tractor batteries and if the battery is fully charged it will only draw the current necessary to keep the charge topped off - a 2 amp charger would provide the same current. the 400 amps would only be drawn if the battery is depleted and wants to pull that much current to charge it. obviously 400 amps would kill our small batteries so the charger is sized to the battery. Some batteries are designed to have a charger, a trickle charger, connected to them all the time. Others don't profit from that same platform and work better with a maintainer. Look at your car battery. how is it used? it's used to start the car, then get recharged by the alternator, then "float" (trickle) while you're driving. it's not used at all while the engine is running because the alternator is providing all the electricity you need. With generators the battery provides some electricity when the engine is idling low because the generator cant make electricity if it's not turning fast enough. So with our tractors and headlights on, if the engine is fast the generator provides the electricity, at idle the lights dim - the battery is doing the work. Anyway, back to the car, once you've gotten home, the battery is now sitting open until tomorrow morning when you go back to work. it's designed to be used in cycle service - use it, charge it, then leave it alone for half a day. The batteries in my offices are designed for float service - they're connected to a charger 24 hours a day for 20-25 years at a time (our batteries do last that long, and longer. i have batteries that have been in service for over 40 years now - and they're just fine.) Automotive batteries tend to perform better with a maintainer because it doesn't keep the battery floating or trickling all the time. Charging too much causes it's on selection of problems! Now if you have a battery that has sulfation you need to remove, you need a trickle charger that will continue to put current into the battery to help convert that lead sulfate back into active material. I created my own maintainer for my diesel generator - a start battery with a 1 amp trickle charger and a vacation light timer I have set to charge 30 minutes every 12 hours. My last start battery for that generator was 18 years old when I used it for the core charge for its replacement. As a side note, one of my offices here in connecticut has some very large batteries and some very large chargers. each charger can put out 220 aps and there are 52 of them connected together - over 11,000 amps of battery charger in one spot all connected together!
c

[welderrx]

Big Bill, if you have a rural king in your area you'll find their battery prices are quite reasonable. Where I got my wifes car battery a month and a half ago. Also regarding the battery box what is the thinking behind the plastic box? Not criticizing just curious. As glen showed that is what the original box looked like and basically every Farmall tractor had a metal box for the batter in it.

No Rural King stores in New England. If there were, Tractor Supply would be gone!

Ed

We used to have central tractor in the Northeast which was awesome then Quality Farm bought them and proceeded to go belly up. TSC bought up what was left it's funny the old Quality store in PA. Has a lot more ag supplies than the new one by my house which seems to cater to the horse crowd backyard chicken farmers and the gardeners. Central tractor partially survived as valubilt for parts any way. The internet came along just in time for the old tractors. TJ

[Redcub]

HalftonStube, thanks for that excellent briefing on batteries and charging. You should write and article for the knowledge base. I sure learned plenty.